Product Introduction
Three-phase dc resistance test instrument is the latest generation product of transformer dc resistance measurement, and is designed to optimize the large-capacity transformerthree-phase dc resistance around the group. Transformer three-phase dc resistance around the group can be tested simultaneously. For transformer with load regulating voltage, discharge can be eliminated and straight pick up switch can be adopted. Measurement time is one third of that of traditional Single phasemeasurement standard, which can greatly reduce working time and labor intensity. The direct resistance meter adopts large screen liquid crystal display, with a clear and intuitive graphical interface in Chinese, and operation is very simple. Equipped with panel printer and large capacity non-volatile memory, measurement results can be easily stored and printed. Testdata is stable, fast and repeatable, making it a standard choice for dc resistance in scenemeasurement transformer.
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Product functions
Three-circuit synchronous testing
Supports simultaneous measurement of three-phase windings, completing A, B, and C phase DC resistance tests with a single connection.
Test efficiency is approximately 2 to 3 times higher than traditional single-circuit equipment, especially suitable for large-capacity power transformers.
High-precision DC resistance measurement
Adopts constant-current source testing technology with stable output current.
Measurement accuracy is high, meeting the requirements for preventive and acceptance testing of power equipment.
Suitable for resistance measurement of high-voltage, low-voltage, and medium-voltage windings.
Automatic switching of multiple test current levels
Provides multiple test current levels.
Automatically recommends or switches test current based on the measured winding resistance, improving measurement speed and accuracy.
Các thông số kỹ thuật
| Item | Technical specifications and parameters | Remarks |
| Measure current | 1A, 5A, 10A, 20A | / |
| Measure Range | 1A：10mΩ~20Ω | / |
| 5A：1mΩ~4Ω | ||
| 10A：1mΩ~2Ω | ||
| 20A：1mΩ~1Ω | ||
| Sự chính xác | ±0.2%（full range） | / |
| Data Storage | 255 | |
| Trưng bày | LCD | Resistance display：4 1/2 bits |
| Maximum resolution | 0,1mΩ | / |
| Nguồn cấp | AC 220V±22V，50Hz±2 Hz | Fuse 5A |
| Maximum Power Dissipation | 300W | Test current：10A/hour |
| Môi trường làm việc | Temperature：0℃～40℃ | / |
| Relative Humidity：≤80%RH | ||
| Kích thước | 200╳400╳280 (mm) | / |
| Cân nặng | 6kg | Including accessories |
Tính năng sản phẩm
1. The three-phase DC resistance tester can simultaneously test the DC resistance of the three-phase windings of transformers, greatly reducing measurement time
2. Can quickly and accurately measure the DC resistance of transformer windings
3. Equipped with comprehensive protection functions
4. Compact in size and easy to carry
5. LCD full English menu, easy and intuitive operation
6. Fast testing speed, high accuracy, good data repeatability, and strong anti-interference ability
Application Scenarios
Preventive maintenance and condition assessment of substation main transformers — Conduct periodic DC resistance testing on long-term in-service oil-immersed transformers, dry-type transformers, and special transformers. During equipment outage maintenance, measure three-phase winding resistance values and three-phase imbalance rates to determine whether there are hidden issues such as loosening, poor contact, or overheating aging at winding connection points, providing a basis for transformer condition assessment and maintenance decision-making.
On-load tap-changer performance inspection and fault diagnosis — Perform resistance variation analysis at different tap positions for power transformers with voltage regulation capability. By measuring winding DC resistance at different tap positions, the contact condition of the tap changer contacts can be effectively evaluated, and abnormalities such as contact erosion, oxidation, or mechanical sticking can be identified, improving the operational reliability of the voltage regulation system.
Quality acceptance after major overhaul of large power transformers — Conduct restorative testing on transformers that have undergone cover-lifting inspection, winding repair, or internal treatment. After major overhaul is completed, use three-circuit synchronous measurement to quickly verify winding repair quality, confirm that winding connections are reliable and three-phase resistance consistency meets requirements, preventing equipment re-outage due to repair process issues.
Maintenance and testing of step-up transformers and auxiliary transformers in power plants — Applied to operation and maintenance of large transformers in thermal, hydro, nuclear, and new energy power plants. For key equipment such as main step-up transformers, auxiliary transformers, and excitation transformers in power generation systems, regular DC resistance testing can promptly identify abnormal winding changes, ensuring long-term stable operation of the power plant.
FAQ about Three-circuit Transformer DC Resistance Tester
Q:What is a three-circuit transformer DC resistance tester, and why is it needed?
A:A three-circuit transformer DC resistance tester is a specialized power testing device used to measure the DC resistance value of transformer windings. By applying a stable DC test current to the windings and measuring resistance variations, it can determine winding connection status, conductive circuit quality, and tap changer operating condition.
Compared with traditional single-circuit test equipment, the three-circuit tester can measure all three-phase winding resistances simultaneously, reducing the number of on-site reconnections and waiting time. It is particularly suitable for rapid testing of large power transformers, main transformers, and complex power equipment.
Q:What is the difference between a three-circuit transformer DC resistance tester and a standard single-circuit tester?
A: The three-circuit transformer DC resistance tester uses a multi-channel synchronous measurement method, enabling simultaneous data acquisition from all three-phase windings, whereas standard single-circuit equipment typically requires phase-by-phase testing.
The main differences include:
Different testing efficiency: The three-circuit device completes three-phase measurement with a single connection, significantly reducing test time.
Higher data consistency: Simultaneous testing minimizes the impact of different times and environmental factors on measurement results.
Broader application range: More suitable for large transformers, on-site maintenance, and batch testing tasks.
Simplified operation process: Reduces manual reconnection and improves on-site testing safety.
Q: Why is the three-circuit transformer DC resistance tester suitable for testing large power transformers?
A: The winding resistance of large power transformers is typically low, while the inductance is large, requiring a longer stabilization time with traditional test equipment. The three-circuit transformer DC resistance tester features strong output capability and synchronous measurement technology, enabling rapid establishment of stable test conditions and improving testing efficiency for large-capacity transformers.
Its advantages include:
Suitable for testing transformers of high capacity and high voltage levels;
Shortens winding stabilization time;
Reduces on-site outage testing time;
Improves maintenance efficiency and safety.
